Safety catch for elevators, lifts, or the like



' 1,633 836 June 1927' .1. WUSTENHC'JFER SAFETY CATCH FOR ELEVATORS, LIFTS, OR THE LIKE Filed Sept. 23, 1926 2 Sheets-Sheet 1 Fig.1

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Filed Sept. 23. 1926 Patented June 28, 1927.

UNITED STATES PATENT OFFICE.

- crux-res w'bs'rnmrornn, or non'rmmn, GERMANY.

SAFETY CATCH non ELEVATORS, LIr'rs, on man 1.11m.

Application filed September 23, 1926. Serial No. 137,196, and in Germany December 27,1924.

Safety catches for elevators, lifts or the like have becomeknown, in which the braking of. the dropping elevator-cage is produced-by doing cutting work. With this 6 object in view tools are arranged on the cage which, when. the hoisting rope breaks, are automatically brought into operative position whereupon they execute their cutting work on the cage-guides.

Safety-catches of this type present the serious inconvenience that the guide bars, i. e. very important'constituents of the elevators and of the shaft timbering, are put under stress. If these catches work under unfavorable conditions, i. e. if a fully loaded cage drops at a maximum'speed, the guide bars, on which the whole cutting work is done, are weakened and damaged in such a manner, that they will have to be renewed,

In connection with safety-catches which are provided with dentate or toothed catch claws or brakingrollers, it has been proposed to arrange special boardings or brake-beams,

separate from the ide bars, with which boardings or brakeearns the gripping elements co-operate. These means are however of no advantage because the necessary repairs have merely been transferred from the guide bars to other elements of the shaft which must be also of very strong construc tion, so that the work of the elevator is disturbed-in thesame manner as before if the catching device has functioned.

4 The resent invention has for its object 85 to avoi these inconveniences essentially by making the tools, arranged on the cage and getting into the working position upon the brealn'ng of the hoisting rope, cooperate with special workieces or elements which are 40 arranged on t e shaft in continuous succession but removable so that the tools will out off these pieces of material by cutting, planing, chipping, grooving, shearing or in a similar manner. The invention abandons completely. the braking work on the guide bars or on s ecial boardings arrangedin the shaft or on rake-beams and utilizes special work-pieces for consuming the energy of fall of the cage by the work of tools.

work pieces may be fixed on the guide beams.

After breaking of the hoisting rope only a certain number of these work pieces aredamaged, while the guide beams remain mtact. As soon as the ropev has been re-attached the elevator can Proceed its work These whilst the damaged work pieces are renewed at convenient occasion.

From the special work pieces arranged in accordance with the invention the great advantage results that they exclusively serve for consuming work, no other elements of construction being used for this purpose. By 'ving to these work pieces or elements a suitable shape they can be perfectly adapted to the tools mounted on the cage so that, on the one hand, a secure engaging of the tools into the work elements is ensured and, on the other hand, the work proceeds smoothly, so as to continuously consume the energy of fall, and in such a manner that neither-lmportantparts of the elevator are injured nor clogging of the tools occurs. With this object in view the work piece or elements are preferably made of such dimensions that by each element or by a group of work elements arranged at the same height onl a certain portion of the total braking work 1s done, so that a number of successive work elements will be utilized till the total effect, i. e. the stopping of the cage, has been attained. Every individual work element is, in accordance with the invention, thickened in wedgeshape from above downward. In this manner not only the penetrating of the cutting edges of the tools into the material of the work element is considerably facilitated, so that no idle slipping can occur, but the-effeet is further obtained that the shaping or planing lmives have to detach from each work element a cuttin or chip of a thickness which increases om above to below. On each work element the energy of fall of the cage encounters, therefore, an increasing resistance. When, at the moment of breaking of the rope, the device begins to operate, the tools, coming in operative position, brake, owing to this shape of the work ele- -ments, the cage at first softly and consume then by increasing work a portion of the fall ener On the next following work element t e tools again begin to act softly to consume at increasing thickness of the cutting another portion of the fall energy, and so forth, until the ca e has been stop ed. In this manner it is possi 10 to catch the alling cage almost without shock and to stop the same, on a longer braking travel, in a sliding motion which becomes gradually slower, without appreciable shocks.

The stepwise braking of the cage as 'described above may be further improved by arranging in one row of work elements successively work elements consisting of material of different hardness (wood or metal), so that the consumption of energy is increased by. successively cutting ofli' work elements of different hardness. As, evidently, the energy consuming rows of. work elements are arran ed on either side of the cage in the sha t "the Wedge-shaped work elements in the two rows might be displaced the one with regard to the other so that the beginning or end of one work element. in one row is situatedat the same height as the center of a work element in the other row. Thus the stepwise increasing braking action is preserved for each row so that the effect onto the whole cage remains uniform.

An embodiment of the invention is shown, by way of example, on the accompanying drawing, in which Fig. 1 shows a part of the improved safety catch in side elevation.

Figs. 2 to 4 illustrate different shapes for thelworking edges of the planing or cutting too s.

Fig. 5 is a view showing the arrangement of the work elements at both sides of thg cage and illustrating a braking action.

In Fig. 1 a is a cage, b the ide bars for the same. On two opposite sides of the cage a either at the top or at the bottom or at the top and at the bottom levers '0 are pivotally mounted which have cutting edges 0 at their free ends so that they form planing or cutting tools. The levers c are connected b means of counter arms d and suitable ro s with the hoisting rope so that the tools a adopt the position indicated in dot and dash lines when'the rope is taut. When the rope breaks the tools are pivoted by the action of springs or the like into the position shown in full lines, the counter arms d bearing then against abutments f of the cage a.

According to the invention work pieces or elements g of suitable metal, for instance iron, are fixed in a vertical continuous row on the guide bars 6 of the cage. These work elements g adopt with regard to the tools 0 such a position that the tools come into touch with the work elements g1 as soon as the tools, owing to the breaking of the rope, are turned into the operative position. The tools act then by a laning or chopping action upon the work e ements g, i. e. they cut off from the same cuttings or chips 9 I of certain thickness, whereby the fall energy of the cage is gradually consumed so thatthe cage is stopped. a

The wdrk elements 9 are preferably, on their sides facing the tools, thickened in wedge-shape from abovedownwards, wherefrom results that the cuttings to be cut oil each work element get gradually thicker 1,eas,sso

towards the bottom end of the work element.

In this manner each work element opposes to the tool cutting into it a resistance which increases from above to below.

It is further advisable to use work elements which. have, on the side facing the tools, undulations extending transversely to the direction of movement of the cage, as shown on the work element 9 so that the work elements present permanently a secure contacting surface to the tools in operative position.

The planing or cutting tools may have either a continuous working edge 0 as shown in Fig. 2, or a working edge 0 composed of square teeth as shown in Fig. 3, or composed of pointed teeth a as shown in- Fig. 4.

The work pieces or elements 9 are removably fixed on the guide bars I) so that the work elementswhich have been damaged by the catchin of a cage can be rapidly re placed by fres elements.

In some lifts or elevators it is usual to securely hold the cage in the prescribed height with regard to the junction line at 90 the loading or chargin places by means of bolts .or the like pushe under thecage. As at this occasion slackening of the rope occurs frequently, whereby the toolsc would be turned partly or completely into the working osition, it is advisable to omit certain wor elements g at the loading or charging places.

Many modifications of construction or other embodiments of the invention are evidently possible.

1'. A device for catching fallin cages comprising in combination with t e ca e and with the guide bars for the cage, too s on the ca e and adapted to be brought automatical y into the operative position when the rope breaks, and work pieces or elements detachably fixed in a continuous row on said uide bars and designed to be worked upon y said tools.

2. A device for catching fallin cages comprising in combination with the cage and with the guide bars for the cage, tools on the cage and adapted to be brought automatically into the operative position when the rope breaks, and work elements detachably fixed in a continuous row on said guide bars and designed to be worked upon by said tools, said work elements being thicksued in wedge-shape towards the bottom end on the side facing said tools.

3. A device for catching falling cages comprising in combination with the cage and with the guide bars for the cage, tools 1 on the cage and adapted to be brought antomatically into the operative position when the rope breaks, and work elements detachably fixed in a continuous row on said guide bars and designed to be worked upon by said tools, sai

tools, wedge-shape towards the bottom end on the and having on then rope breaks, an

said work elements being thickened in side facing said tools, working surfaces undulations transversely to the direction of travel of said cage.

4. A device for catching fa ling cages comprising in combination with the cage. and with the guide bars for the cage, tools on the cage and adapted to be brought automatically into the operative position when the rope-breaks, and Work ably fixed ina continuous row on said guide bars and designed to be worked upon by said tools, the upper work elements ofeach group of successive elements bein of softer ma terial and the lowerwork e ements being of harder material.

5. A device 1 for catching fallin cages.

the cage and y comprising in combination with with theguide bars for the cage, tools on thecage and adapted to be brought automatically into the o e'rative position when the work elements detachably fixed in a continuous row on said guide bar and designed to be worked upon by said work elements being thickened in wedge shape towards the bottom end on the ,'ments on one side of the ca e same height as the center 0 the Work eleelements detach-- side'facin said tools, the work elements on the ide ar at one side of said on e being disp aced with regard to the work e ements on the guide bar at the opposite side of said cage so that the lower on of the work elestand at the ments on the other side of the cage.

6. A' device for catching fallin cages comprising in combination with t e c e and with the guide bars on the cage and adapted to be broug t automatically into the operative position when the rope breaks, and work elements detachfor the ca e, too s ably fixed in a continuous row on said guide bars and designed to be worked upon b said tools, the work elements on the ui e bar at one side of said cage being disp aced with regard to the work elements on the guide bar at the opposite side of said cage so that the up er end of the work elements on one side 0 the cage stand at the same height as the center of the work elements on the other side of the (ma In testimony whereof I .a u my signature.

V JULI S WUSTENHOF R. 

